Roll stability control system for an automotive vehicle using an external environmental sensing system

ABSTRACT

A roll stability control system ( 18 ) for an automotive vehicle ( 10 ) includes an external environment sensing system, such as a camera-based vision system, or a radar, lidar or sonar-based sensing system ( 43 ) that generates image, radar, lidar, and/or sonar-based signals. A controller ( 26 ) is coupled to the sensing system and generates dynamic vehicle characteristic signals in response to the image, radar, lidar, or sonar-based signals. The controller controls the rollover control system ( 18 ) in response to the dynamic vehicle control signal. The dynamic vehicle characteristics may include roll related angles, angular rates, and various vehicle velocities.

BACKGROUND OF INVENTION

The present invention relates generally to a dynamic behavior controlapparatus for an automotive vehicle, and more specifically, to a methodand apparatus for controlling the roll characteristics of the vehicle bydetermining roll characteristics using at least in part a camera, radar,lidar, or sonar-based system.

Dynamic control systems for automotive vehicles have recently begun tobe offered on various products. Dynamic control systems typicallycontrol the yaw of the vehicle by controlling the braking effort at thevarious wheels of the vehicle. Yaw control systems typically compare thedesired direction of the vehicle based upon the steering wheel angle andthe direction of travel. By regulating the amount of braking at eachcorner of the vehicle, the desired direction of travel may bemaintained. Typically, the dynamic control systems do not address rollof the vehicle. For high profile vehicles in particular, it would bedesirable to control the rollover characteristic of the vehicle tomaintain the vehicle position with respect to the road. That is, it isdesirable to maintain contact of each of the four tires of the vehicleon the road.

In vehicle roll stability control it is desired to alter the vehicleattitude such that its motion along the roll direction is prevented fromachieving a predetermined limit (rollover limit) with the aid of theactuation from the available active systems such as controllable brakesystem, steering system and suspension system. Although the vehicleattitude is well defined, direct measurement is usually impossible.

There are two types of vehicle attitudes needed to be distinguished. Oneis the so-called global attitude, which is sensed by the angular ratesensors. The other is the relative attitude, which measures the relativeangular positions of the vehicle with respect to the road surface onwhich the vehicle is driven. The global attitude of the vehicle isrelative to an earth frame (or called the inertia frame), sea level, ora flat road. It can be directly related to the three angular rate gyrosensors. While the relative attitude of the vehicle measures therelative angular positions of the vehicle with respect to the roadsurface, which are always of various terrains. Unlike the globalattitude, there are no gyro-type sensors that can be directly related tothe relative attitude. A reasonable estimate is that a successfulrelative attitude sensing system utilizes both the gyro-type sensors(when the road becomes flat, the relative attitude sensing systemrecovers the global attitude) and some other sensor signals.

One reason to distinguish relative and global attitude is due to thefact that vehicles are usually driven on a three-dimensional roadsurface of different terrains, not always on a flat road surface.Driving on a road surface with a large road bank does increase therollover tendency, i.e., a large output from the global attitude sensingsystem might well imply an uncontrollable rollover event regardless ofthe flat road driving and the 3-D road driving. However driving on athree-dimensional road with moderate road bank angle, the globalattitude may not be able to provide enough fidelity for a rollover eventto be distinguished. Vehicular rollover happens when one side of thevehicle is lifted from the road surface with a long duration of timewithout returning back. If a vehicle is driven on a banked road, theglobal attitude sensing system will pick up certain attitude informationeven when the vehicle does not experience any wheel lifting (four wheelsare always contacting the road surface). Hence a measure of the relativeangular positions of the vehicle with respect to the portion of the roadsurface on which the vehicle is driven provides more fidelity thanglobal attitude to sense the rollover event when the vehicle is drivenon a road with a moderate bank angle. Such an angle is calledbody-to-road roll angle and it is used as one of the key variables inthe roll stability control module to compute the amount of actuationneeded for preventing an untripped rollover event.

When the vehicle does not have one side lifted, U.S. Pat. No. 6,556,908does provide a method to calculate the relative attitudes and theiraccuracy may be affected by the vehicle loading, suspension and tireconditions. However, during a potential rollover event, such a relativeroll angle is not a good measure of the true relative roll angle betweenvehicle body and the road surface. U.S. patent application Ser. No.10/459,697, filed Jun. 11, 2003 (Attorney Docket No. 201-0938 (FGT1660))provides another way to compute the true relative roll angle during apotential rollover event. This application is suited for cases wherevehicle loading and suspension conditions are very close to the nominalsystems. If the vehicle has large loading variations (especially roofloading), potential inaccuracy could cause false activations in rollstability controls.

During a potential rollover event, one or two wheels on the inside ofthe vehicle turn are up in the air and there is an angle between theaxle of the lifted wheel and road surface. Such an angle is called awheel departure angle. If such a wheel departure can be somehowcharacterized, the true body-to-road roll angle can be conceptuallyobtained as the sum of the wheel departure angle and the relative rollangle calculated in U.S. Pat. No. 6,556,908.

Another way to capture the true body-to-road roll angle is to use theresultant angle obtained by subtracting the road bank angle for theglobal roll angle calculated for example in U.S. Pat. No. 6,631,317.Although this method is theoretically feasible, it has inevitabledrawbacks. The first drawback lies in the computation of the road bankangle, since there is no robust and accurate computation of road banksusing the existing sensor set. Secondly, the global roll anglecomputation as shown in U.S. Pat. No. 6,631,317 may be affected by theaccuracy of the low frequency bank angle estimation.

Therefore, the aforementioned two methods of computing the body-to-roadroll angle may not deliver accurate enough body-to-road roll angle forroll stability control purpose in certain situations.

Various accident avoidance systems are being developed that have camerasmounted in the vehicle. Some systems also use the camera in determiningwhen to deploy an airbag. These systems, however, do not prevent thevehicle from rolling over. Such systems merely react to a condition toreduce occupant injury.

Therefore, it is desirable in vehicle dynamics control, especially forroll stability control to detect accurately various roll anglesassociated with the vehicle and road to accurately predict the true rollposition of the vehicle to properly activate the vehicle controlsystems.

SUMMARY OF INVENTION

One advantage of the invention is that the camera, radar, lidar, orsonar-based systems can be used alone or together with various sensors.The camera, radar, lidar, or sonar-based systems may provide a check tothe sensor outputs.

Other objects and features of the present invention will become apparentwhen viewed in light of the detailed description of the preferredembodiment when taken in conjunction with the attached drawings andappended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagrammatic view of a vehicle with variable vectors andcoordinated frames according to the present invention.

FIG. 2 is a block diagram of a stability system according to the presentinvention.

FIG. 3 is an end view of an automotive vehicle on a bank withdefinitions of various angles including global roll angle, relative rollangle, wheel departure angle (WDA), road bank angle and body-to-roadangle.

FIG. 4 is a block diagrammatic view of the controller of the presentinvention.

FIG. 5 is a block diagrammatic view of the rollover control law of FIG.4.

FIG. 6 is a block diagrammatic view of the handling loss control law ofFIG. 4.

FIG. 7 is a perspective view of a field of view of a camera from whichimage signals are derived.

DETAILED DESCRIPTION

In the following figures the same reference numerals will be used toidentify the same components.

The present invention may be used in conjunction with a rollover controlsystem for a vehicle. The system may be used with various dynamiccontrol systems such as, but not limited to, anti-lock brakes, tractioncontrol and yaw control systems. The present invention will be discussedbelow in terms of preferred embodiments relating to an automotivevehicle moving in a three-dimensional road terrain. Further, the variousimage detection and sensors may be used alone or in various combinationsdepending on the conditions. For example, sensors may be used to checkthe image or radar signals or vice versa.

Referring to FIG. 1, an automotive vehicle 10 with a safety system ofthe present invention is illustrated with the various forces and momentsthereon during a rollover condition. Vehicle 10 has front right andfront left tires 12 a and 12 b and rear right tires 13 a and left reartires 13 b respectively. The vehicle 10 may also have a number ofdifferent types of front steering systems 14 a and rear steering systems14 b including having each of the front and rear wheels configured witha respective controllable actuator, the front and rear wheels having aconventional type system in which both of the front wheels arecontrolled together and both of the rear wheels are controlled together,a system having conventional front steering and independentlycontrollable rear steering for each of the wheels, or vice versa.Generally, the vehicle has a weight represented as Mg at the center ofgravity of the vehicle, where g=9.8 m/s² and M is the total mass of thevehicle.

The sensing system 16 may use a standard yaw stability control sensorset (including lateral accelerometer, yaw rate sensor, steering anglesensor and wheel speed sensor) together with a roll rate sensor and alongitudinal accelerometer. Of course, the actual sensors used will varydepending on the type of dynamic control system. The various possiblesensors will be further described below. The wheel speed sensors 20 aremounted at each corner of the vehicle, and the rest of the sensors ofsensing system 16 are preferably mounted directly on the center ofgravity of the vehicle body, along the directions x, y and z shown inFIG. 1. As those skilled in the art will recognize, the frame from b₁,b₂ and b₃ is called a body frame 22, whose origin is located at thecenter of gravity of the car body, with the b₁ corresponding to the xaxis pointing forward, b₂ corresponding to the y axis pointing off thedriving side (to the left), and the b₃ corresponding to the z axispointing upward. The angular rates of the car body are denoted abouttheir respective axes as ω_(x) for the roll rate, ω_(y) for the pitchrate, and ω_(z) for the yaw rate. The present invention calculationspreferably take place in an inertial frame 24 that may be derived fromthe body frame 22 as described below.

As will be described below, the sensing system 16 may also include alidar, radar and/or sonar sensor, cameras and/or a GPS system (all ofwhich are shown in FIG. 2 below).

The angular rate sensors and the accelerometers are mounted on thevehicle car body along the body frame directions b₁, b₂ and b₃, whichare the x-y-z axes of the vehicle's sprung mass.

The longitudinal acceleration sensor is mounted on the car body locatedat the center of gravity, with its sensing direction along b₁-axis,whose output is denoted as a_(x). The lateral acceleration sensor ismounted on the car body located at the center of gravity, with itssensing direction along b₂-axis, whose output is denoted as a_(y).

The other frame used in the following discussion includes the roadframe, as depicted in FIG. 1. The road frame system r ₁r₂r₃ is fixed onthe driven road surface, where the r₃ axis is along the average roadnormal direction computed from the normal directions of thefour-tire/road contact patches.

In the following discussion, the Euler angles of the body frame b₁b₂b₃with respect to the road frame r ₁r₂r₃ are denoted as θ_(xbr), θ_(ybr)and θ_(zbr), which are also called the relative Euler angles.

Referring now to FIG. 2, roll stability control system 18 is illustratedin further detail having a controller 26 used for receiving informationfrom a number of sensors which may include speed sensors 20, a yaw ratesensor 28, a lateral acceleration sensor 32, a roll rate sensor 34, avertical acceleration sensor 35, a longitudinal acceleration sensor 36,a pitch rate sensor 37, and steering angle position sensor 38. Sensors28-38 may be part of an integrated measurement unit 40 or IMU.

In one embodiment the sensors are located at the center of gravity ofthe vehicle. Those skilled in the art will recognize that the sensor mayalso be located off the center of gravity and translated equivalentlythereto.

Lateral acceleration, roll orientation and speed may be obtained using aglobal positioning system (GPS) 41.

The controller 26 may also be coupled to a lidar, radar, or sonar 42.The lidar, radar, or sonar 42 may be used to generate a velocity signalof an object. The radar or lidar may also be used to generate atrajectory signal of an object. Likewise, the velocity of the vehicle invarious directions may be obtained relative to a stationary object. Alidar, radar, or sonar sensor 42 may be mounted in various positions ofthe vehicle including the front, sides and/or rear. Multiple sensors 42may also be employed in multiple locations to provide multipleinformation from multiple positions of the vehicle.

Controller 26 may also be coupled to a camera system 43 having cameras43 a-43 e. A stereo pair of cameras 42 a, 42 b may be mounted on thefront of the vehicle to detect target objects in front of the vehicle,to measure the object size, range and relative velocity and to classifythose objects into appropriate categories. Camera 43 c may be mounted onthe right side of the vehicle, camera 43 d may be mounted on the leftside of the vehicle, and camera 43 e may be directed rearward of thevehicle. All or some of the cameras may be used in a commercialembodiment. Also, a stereo pair of cameras 43 a, 43 b may be replaced bya single camera (43 a or 43 b) depending on the roll condition measuredby the system. Various types of cameras would be evident to thoseskilled in the art. Various types of cameras such as a CMOS-type cameraor a CCD-type camera may be implemented to generate various imagesignals. As will be further described below, the various image signalsmay be analyzed to determine the various dynamic conditions of thevehicle.

Based upon inputs from the sensors and/or cameras, GPS, and lidar orradar, controller 26 may control a safety device 44. Depending on thedesired sensitivity of the system and various other factors, not all thesensors 28-38, cameras 43 a-43 c, lidar or radar 42, or GPS 41 may beused in a commercial embodiment. Safety device 44 is part of a vehiclesubsystem control. Safety device 44 may control a passive safety device46 such as an airbag or a steering actuator 48, a braking actuator 50 atone or more of the wheels 12 a, 12 b, 13 a, 13 b of the vehicle. Engineintervention 52 may act to reduce engine power to provide a safetyfunction. Also, other vehicle components such as a suspension control 54may be used to adjust the suspension to prevent rollover. An anti-rollbar system 56 may be used to prevent rollover. The anti-roll bar system56 may comprise a front or rear active anti-roll bar, or both. It shouldalso be noted that the systems 48-56 may act alone or in variouscombinations to prevent the vehicle from rolling over. Certain systems48-56 may act to prevent rollover where various dynamic conditions aresensed.

A warning device 60 may also be coupled to controller 26. Warning devicemay warn of various conditions such as an impeding rollover or anapproach of an in-path object. The warnings are provided in time for thedriver to take evasive action. The warning device may be a visualdisplay such as warning lights or an alpha-numeric display such an LCDscreen. The warning device may also be an audible display such as awarning buzzer, chime or bell. The warning device may also be a hapticwarning such as a vibrating steering wheel. Of course, a combination ofaudible, visual, and haptic display may be implemented.

A level-based system 62 may also be coupled to controller 18.Level-based system 62 uses the pitch level or angle of the vehicle toadjust the system. Level-based system 62 may, for example, be aheadlight adjustment system 64 or a suspension leveling system 66.Headlight adjustment system 64 adjusts the beam pattern downward for aloaded vehicle. Suspension leveling system 66 adjusts the suspension atthe various corners of the vehicle to maintain the vehicle bodyrelatively level. The level-based system 62 may also make an adjustmentbased on the roll angle of the vehicle.

Roll rate sensor 34 and pitch rate sensor 37 may sense the rollcondition of the vehicle based on sensing the height of one or morepoints on the vehicle relative to the road surface. Sensors that may beused to achieve this include a radar-based proximity sensor, alaser-based proximity sensor and a sonar-based proximity sensor.

Roll rate sensor 34 and pitch rate sensor 37 may also sense the rollcondition based on sensing the linear or rotational relativedisplacement or displacement velocity of one or more of the suspensionchassis components which may include a linear height or travel sensor, arotary height or travel sensor, a wheel speed sensor used to look for achange in velocity, a steering wheel position sensor, a steering wheelvelocity sensor and a driver heading command input from an electroniccomponent that may include steer by wire using a hand wheel or joystick.

The roll condition may also be sensed by sensing the force or torqueassociated with the loading condition of one or more suspension orchassis components including a pressure transducer in an act of airsuspension, a shock absorber sensor such as a load cell, a strain gauge,the steering system absolute or relative motor load, the steering systempressure of the hydraulic lines, a tire laterally force sensor orsensors, a longitudinal tire force sensor, a vertical tire force sensoror a tire sidewall torsion sensor.

The roll condition of the vehicle may also be established by one or moreof the following translational or rotational positions, velocities oraccelerations of the vehicle including a roll gyro, the roll rate sensor34, the yaw rate sensor 28, the lateral acceleration sensor 32, avertical acceleration sensor, a vehicle longitudinal accelerationsensor, lateral or vertical speed sensor including a wheel-based speedsensor, a radar-based speed sensor, a sonar-based speed sensor, alaser-based speed sensor or an optical based speed sensor.

Steering control 48 may control the position of the front right wheelactuator, the front left wheel actuator, the rear left wheel actuator,and the right rear wheel actuator. Although as described above, two ormore of the actuators may be simultaneously controlled. For example, ina rack-and-pinion system, the two wheels coupled thereto aresimultaneously controlled. Based on the inputs from sensors 28 through38, controller 26 determines a roll condition and controls the steeringposition of the wheels.

Speed sensor 20 may be one of a variety of speed sensors known to thoseskilled in the art. For example, a suitable speed sensor may include asensor at every wheel that is averaged by controller 26. Preferably, thecontroller translates the wheel speeds into the speed of the vehicle.Yaw rate, steering angle, wheel speed and possibly a slip angle estimateat each wheel may be translated back to the speed of the vehicle at thecenter of gravity. Various other algorithms are known to those skilledin the art. Speed may also be obtained from a transmission sensor. Forexample, if speed is determined while speeding up or braking around acorner, the lowest or highest wheel speed may not be used because of itserror. Also, a transmission sensor may be used to determine vehiclespeed.

Controller 26 may include an integrated roll control system 58 to detectand prevent rollover. While these functions are provided by controller26, several controllers may be used to provide various determinationsand control functions. The controller 26 may be programmed to providethe various functions.

Referring now to FIG. 3, the relationship of the various angles of thevehicle 10 relative to the road surface 11 is illustrated. The presentteaching determines a wheel departure angle θ_(wda), which is the anglefrom the axle or the wheel axis to the road surface 11. Also shown is areference road bank angle θ_(bank), which is shown relative to thevehicle 10 on a road surface. The vehicle 10 has a vehicle body 10 a andvehicle suspension 10 b. The relative roll angle θ_(xr) is the anglebetween the wheel axle and the body 10 a. The global roll angle θ_(x) isthe angle between the horizontal plane (e.g., at sea level) and thevehicle body 10 a.

Referring now to FIG. 4, controller 26, and in particular the integratedroll control system 58, is illustrated in further detail. The integratedroll control system 58 includes rollover control law 80 and handlingloss control law 82. The rollover control law 80 and handling losscontrol law 82 are coupled to a roll moment command 84. The rollovercontrol law ultimately determines the rollover potential of the vehiclefrom the various inputs. The handling loss control 82 determines a lossof handling of the vehicle from the inputs. Handling loss may be wheelslocking or slipping or the like. The output of the roll moment command84 is used to control the brake pressure priority logic 86 and otherpriority logic 88. The other priority logic may include at least one ofthe steering system (actuator) 48, engine intervention 52, suspensioncontrol 54 and anti-roll bar system 56. It should be noted that in asimple system only one system such as braking or steering may becontrolled to prevent rollover performed and thus other priority controllogic may be eliminated. The brake pressure priority logic 86 and theother priority control logic 88 receive the roll angle from the rollmoment command 84 and controls brake control 50 or other systems 52-56.The control provided by the brake control 50 and the other systems arefed back to the system through at least one of the roll rate sensor 34,longitudinal acceleration sensor 36, lateral acceleration sensor 32,wheel speed sensors 20, steering angle position sensor 38 and the camerasystem 43. The information from these systems is fed back to the yawstability controller 102, an anti-lock brake system 104, and a tractioncontrol system 106. The anti-lock brake system 104 generates a brakecontrol signal. The traction control system 106 generates a braketraction control signal. The yaw stability controller 102 generates abrake yaw control signal. The yaw stability controller 102 may alsoprovide an input with respect to the yawing of the vehicle to the otherpriority logic 88 and the brake pressure priority logic 86. Thecontrollers 102, 104, 106 may be separate devices or integrated intocontroller 26 above. Each controller 102, 104, 106 is part of a safetysystem 44 of FIG. 2. The brake pressure priority logic 86 receives thebrake control signals and generates brake controls to prevent thevehicle from rolling over. The other systems including but not limitedto the steering actuator 48, engine intervention 52, suspension control54, and the anti-roll bar system 54 may also be controlled andcoordinated with the brake control to prevent the vehicle from rollingover or losing handling. The anti-roll bar system, or other systems maybe used to simultaneously control rollover while the brake system may beused to control yawing or vice-versa after both systems are used forrollover control. The anti-roll bars or other systems may also becontrolled sequentially with the brakes to prevent rollover.

Referring now to FIG. 5, rollover control law 80 is illustrated infurther detail. Rollover control law 80 may comprise a rollover detector110 that is coupled to the various sensors. Further, a roll anglecomputation 112 may also be performed by rollover control law 80. Therollover detector detects the presence of rollover and determines a rollangle of the vehicle. Rollover detector may, for example, provide asingle wheel lift identification 114 or a double wheel liftidentification 116. The output of the single wheel lift identification114, double wheel lift identification 116, and roll angle computation112 are provided to a rollover feedback control computation 118. Therollover feedback control computation generates a moment M_(R) that isthe roll moment of the vehicle. Thus, by knowing the roll moment of thevehicle the roll moment can be counteracted using one of the systemsdescribed below.

Referring now to FIG. 6, handling roll control law 82 may also consistof a rollover detector 120 and a roll angle computation 122. The rolldetector in a similar manner to the rollover control law 80 may providean indication of single wheel lift detection 124, or double wheel liftdetection 126. Single wheel lift detection 124, double wheel liftdetection 126, and roll angle computation 122 may be provided to ahandling roll feedback control computation 128 that generates a rollmoment M_(R) of the vehicle. By knowing the roll angle of the vehicle,the roll moment may be counteracted.

Referring now to FIG. 7, a perspective view of a field of view of one orboth of the front cameras is illustrated. Similar views would beavailable to the side cameras. Similar views would also be generatedfrom the rear camera. Many of the calculations from the front camera maybe performed by the rear camera. Based on various cues, various dynamicconditions such as the roll angle, vehicle speed, body-to-road angle,longitudinal and lateral velocities, pitch angle, road departure, anin-path object, wheels lifting, and body slides that may be determined.The front, rear, side, and front or rear and a side camera may be usedto obtain the points or visual cues described below.

One such way in which the roll angle between the body and the roadsurface may be estimated is by determining a road surface plane 140 byidentifying discernable features on the road surface, such as solidlines, dashed lines, cats eyes, or other road surface markings or roadtexture. The range to these features may be determined based on a stereovision-based depth map, monocular vision-based perspective analysis ormatching and scaling the observed feature to a pre-defined feature ofknown dimension. Analysis of the change in perspective of the definedroad surface over time can be used to estimate body to road roll angle.

The global vehicle longitudinal velocity and lateral velocity relativeto the lanes can be determined by measuring the relative velocity ofdefined stationary road cues including points 142, 144, and 146.

The absolute roll angle may be estimated based on analysis of objectswith strong vertical or horizontal structures such as street lights 148,bridges, signs or buildings 150. Such an algorithm uses multiplepossible targets in a filtering strategy to remove outliers to providean accurate result. Further, the global lateral velocity may beestimated based on a measurement of range, range rate, angle, and achange in the stationary structures.

A define horizon line may be used to estimate the absolute roll angle.The horizon 152 is the location in the image where the road approacheszero width. It can be determined by detecting the transition from theground to the sky in the image and/or it may be determined bycalculating the point at which the lanes approach zero width.

The roll rate may be estimated by measuring the change in the roll angleto distant objects such as clouds 154 or mountains 156.

During night conditions, the illumination pattern on the road due to theheadlights and parking lights of the vehicle may be used. Each vehiclehas a unique consistent characteristic of bright spots, dark spots, andbeam cutoff. By analyzing the projected pattern it is possible todetermine the road angle between the vehicle body and the road surface.

Ego-motion may also be analyzed to determine the vehicle motion. Imagevalues in two sequential images are analyzed to determine a best fitmotion that corresponds to the change in the image. The global approachmay be very robust due to varying road and weather conditions. Globalroll rate, pitch rate, yaw rate, lateral and longitudinal speeds may bedetermined. Roll pitch and yaw angles may also be calculated based onthe velocity signals.

The vision sensing system may also be used to detect in-path objectsthat may, for example, present a tripping hazard for the vehicle.

A vision-based, radar-based, or lidar-based sensing system may also beused to detect wet roads, spray and snow conditions.

Tripping objects may be detected in various manners. Tripping objects,such as curbs, are low profile objects that if the vehicle slides intomay cause a rollover. If the vehicle is yawing, the front and sidecameras may be used. Further, the lateral velocity of the vehicle may bedetermined by the side cameras in relation to various objects.Combinations of the side camera and front cameras may be used todetermine the vehicle side slip. In prior systems that use only sensors,thresholds for entering roll stability control and yaw stability controlare set to take into account variability within the sensors. That is,because the angles are not measured directly, signal conditioners areimplemented to estimate the road bank and vehicle roll angle. Byimproving the accuracy of the roll angle, the thresholds for entry intothe yaw stability control events can be reduced allowing yaw stabilitycontrol to activate sooner, if necessary. The present invention alsoimproves entry into a wheel lift detection algorithm. An active wheellift detection scheme starts to detect that the wheels have lifted basedon an increase in roll angle. The threshold for entry is relatively lowdue to the indirect measurements. When a rollover condition isapproaching, the system actively determines whether the wheels arelifted. Thus, a more accurate determination of the roll angle of thevehicle may result in improved entry into the wheel lift detectionstrategy. Thus, the wheel lift detection entry criteria or lift statecan be improved by directly measuring the angle between the vehicle bodyand the road surface with a vision sensor.

The vision sensing system may also be used to differentiate betweenaggressive driving and loss of control conditions by measuring thelateral velocity relative to the lane markings and/or the road edgeswith a vision sensor, the yaw stability control system and the rollstability control system may differentiate between aggressive drivingand potential loss of control conditions. For example, when the vehicleis within the lane markings during aggressive driving, the yaw stabilitycontrol and roll stability control entry thresholds may be increased.Should the vehicle be outside or projected to be outside the vehiclelane markings in the near future, the entry thresholds may be reduced.

In a typical stability control system a plurality of wheel speed sensorsare used to obtain the longitudinal speed of the vehicle. However,during wheel lock or wheel slip conditions if image data is availablefrom the vision system, a determination may be made as to thelongitudinal vehicle velocity from the vision system. Also, aradar-based sensor can measure the longitudinal speed by measuring theDoppler shift of signal reflections off of the road surface. Also, alidar-based sensor can measure the longitudinal speed by measuring therelative velocity to stationary objects. The wheel lock or a heavy wheelslip condition may be determined by monitoring the wheel speeds. If nooutput or near zero output is determined from one of the plurality ofthe wheel speed sensors, wheel lock may be indicated. If one wheel has alow speed relative to the others, wheel slip may be indicated. Thus,when wheel slip or wheel lock is not determined, the system may use theoutput of the wheel speed sensors to determine the longitudinal speed ofthe vehicle. When a wheel lock or wheel slip condition exists, the wheelspeed derived from the image, radar, or lidar signals may be used as anindication of the longitudinal speed of the vehicle.

The present system may also be used to improve the side slip estimationof the vehicle. That is, the image signals generated by the cameras maybe used to estimate the lateral velocity, which in turn may be used inthe body side slip determination. Typically, side slip is measured basedon the wheel speeds, the steering wheel angle, the lateral accelerationand the yaw rate values. However, side slip is difficult to measureaccurately in low friction side slip conditions such as wet or icyroads. The side slip angle is the tangent of the ratio of the forwardvelocity and side velocity of the vehicle. Once the side slip angle isdetermined using the image signal, the dynamic control system may becontrolled. It should also be noted that the longitudinal velocity maybe obtained using the image, radar, or lidar signals or wheel speedsensors as described above.

The image, radar, or lidar-based signals may also be used to estimate alow mu of the vehicle surface. That is, wet or snow covered conditionsmay be estimated using the image, radar, or lidar-based signals.Vision-based sensors can estimate wet or snow covered conditions basedon road texture, reflectivity, and/or color analysis, road spraydetection, or water drop patterns on the camera surface. Radar andlidar-based sensors can estimate wet or snow covered conditions based onanalysis of the signal return. The controller, based upon the image,radar, or lidar-based signals, may generate a low mu identificationsignal of the road surface. The system may also quantify the level of muso as to differentiate wet versus snow-covered roads. That is, a firstlow mu value may be identified as well as a second low mu value lowerthan the first low mu value. The second value may correspond to snowwhereas the first value may correspond to rain. In response to the lowmu identification signal, a dynamics control system may be operated. Forexample, a roll stability control system or a yaw control system mayhave the entry thresholds changed in response to the low muidentification signal.

The image, radar, or lidar-based signals may also be used to determinethe presence of an in-path hazard in response to the image signal. Thedynamics control system may have different strategies based upon whetheror not an object is in the path or not. The different strategies mayinclude the entry criteria for control or the control thresholdscontained therein. The different strategies and entry are vehiclespecific and are determined through vehicle testing. The differencebetween a first control strategy and a second control strategy is thatmore aggressive maneuvers may take place in the presence of an in-pathhazard. Thus, in response to the image, radar, or lidar-based signals, asecond control strategy may be used rather than a first controlstrategy. The dynamic control system is then operated in response to thesecond control strategy. The various types of dynamic control systemsdescribed above such as anti-lock brakes, traction control, rollstability control, and yaw stability control may all benefit from thetwo control strategy approach when an in-path hazard is present.

Another way in which the image signals may be used is for correction ofthe sensor signals from the integrated measurement unit 40. One way inwhich sensor drift may be corrected is to use GPS. GPS provides acorrection mechanism every 20 Hz while IMUs provide a high frequencysignal, for example, in the 143 Hz range. Various angular rates such asroll, pitch and yaw rates may be computed from the image signals. Thatis, because the image signals may directly measure one of the vehicleattitudes or velocities of the vehicle, the sensor drift from theintegrated measurement unit may be periodically corrected. Thecorrection may take the form of correcting the drift error of thevarious signals from the integrated measurement unit. Thus, correctedsensor signals are formed. The corrected sensor signals may then be usedto operate the dynamic control system. As mentioned above, thiscorrection may take place several times a second. For example,correction may take place at a rate of 35 Hz.

Another way in which the image signals may be used is to control thelevel-based system 62 shown in FIG. 2. As mentioned above, thelevel-based system may include a headlight adjustment system 64 or asuspension leveling system 66. Both of those systems may benefit from adetermination of the pitch angle of the vehicle. Thus, the image signalsfrom the vision system may be used by the controller 26 to determine apitch angle estimate. Based upon the pitch angle estimate from the imagesignal, the level-based system may be controlled. In addition, the imagesignals may be used to generate a roll angle estimate. The roll angleestimate together with the pitch angle estimate may be used to controlthe level-based system.

While the invention has been described in connection with one or moreembodiments, it should be understood that the invention is not limitedto those embodiments. On the contrary, the invention is intended tocover all alternatives, modifications, and equivalents, as may beincluded within the spirit and scope of the appended claims.

1. A control system for an automotive vehicle comprising: a camera-basedvision system generating image signals; a rollover control system; and acontroller coupled to the camera system and the rollover control system,said controller generating a dynamic vehicle characteristic signal inresponse to the image signals, said controller controlling the rollovercontrol system in response to the dynamic vehicle control signal.
 2. Acontrol system as recited in claim 1 wherein the dynamic vehiclecharacteristic signal comprises a vehicle roll direction angle signal.3. A control system as recited in claim 1 further comprising a yawcontrol system, wherein said controller chooses between the yawstability control system or the rollover control system in response tothe dynamic vehicle characteristic.
 4. A control system as recited inclaim 1 wherein the dynamic vehicle characteristic signal comprises avehicle pitch angle signal.
 5. A control system as recited in claim 1wherein the dynamic vehicle characteristic signal comprises a lateralvelocity signal.
 6. A control system as recited in claim 1 wherein saidcontroller determines an aggressive driving status or loss of controlstatus in response to the lateral velocity signal, said controlleractivating a yaw stability control system or a rollover control systemin response to determining the aggressive driving status or loss ofcontrol status.
 7. A control system as recited in claim 1 wherein thedynamic vehicle characteristic signal comprises a longitudinal velocitysignal.
 8. A control system as recited in claim 1 wherein the dynamicvehicle characteristic signal comprises a road departure signal.
 9. Acontrol system as recited in claim 1 further comprising a yaw stabilitycontrol signal, said controller controlling the yaw stability controlsystem in response to the road departure signal.
 10. A control system asrecited in claim 1 wherein the dynamic vehicle characteristic signalcomprises an in-path object signal.
 11. A control system as recited inclaim 1 wherein the dynamic vehicle characteristic signal comprises awheel lifted signal.
 12. A control system as recited in claim 1 whereinthe dynamic vehicle characteristic signal comprises a body-to-road anglesignal.
 13. A control system as recited in claim 12 wherein thecontroller enters a wheel lift determination when the body-to-road angleis above a predetermined threshold.
 14. A control system as recited inclaim 1 further comprising generating a plurality of wheel speeds from awheel speed sensors, wherein said controller identifying a wheel slipcondition or wheel lock condition, said controller generating alongitudinal speed signal from the dynamic vehicle characteristic signalduring the wheel slip or wheel lock condition.
 15. A control system asrecited in claim 1 wherein the dynamic vehicle characteristic signalcomprises a body side slip signal.
 16. A control system as recited inclaim 1 wherein the dynamic vehicle characteristic signal comprises arotational moment of inertia signal.
 17. A control system as recited inclaim 1 wherein the camera system comprises a stereo pair of cameras.18. A control system as recited in claim 1 wherein the camera systemcomprises a front camera and side camera.
 19. A control system asrecited in claim 1 wherein the camera system comprises a rear camera andside camera.
 20. A control system as recited in claim 1 furthercomprising a radar, lidar, or sonar-based system generatingenvironmental sensing signals; and said controller generating a dynamicvehicle characteristic signal in response to the image signals and theenvironmental sensing signals.
 21. A method of controlling a rollovercontrol system of automotive vehicle comprising: generating an imagesignal; generating a dynamic vehicle characteristic signal in responseto the image signal; and controlling the rollover control system inresponse to the dynamic vehicle control signal.
 22. A method as recitedin claim 21 wherein generating a dynamic vehicle characteristic signalcomprises generating a vehicle roll direction angle signal.
 23. A methodas recited in claim 21 further comprising a yaw control system, choosingbetween the yaw stability control system or the rollover control systemin response to the dynamic vehicle characteristic signal.
 24. A methodas recited in claim 21 wherein generating a dynamic vehiclecharacteristic signal comprises generating a vehicle pitch angle signal.25. A method as recited in claim 21 wherein generating a dynamic vehiclecharacteristic signal comprises generating a lateral velocity signal.26. A method as recited in claim 25 further comprising determining anaggressive driving status or loss of control status in response to thelateral velocity signal, said controller activating a yaw stabilitycontrol system or a rollover control system in response to determiningthe aggressive driving status or loss of control status.
 27. A method asrecited in claim 21 wherein generating a dynamic vehicle characteristicsignal comprises generating a longitudinal velocity signal.
 28. A methodas recited in claim 21 wherein generating a dynamic vehiclecharacteristic signal comprises generating a road departure signal. 29.A method as recited in claim 28 further comprising a yaw stabilitycontrol signal, said further comprising controlling the yaw stabilitycontrol system in response to the road departure signal.
 30. A method asrecited in claim 21 wherein generating a dynamic vehicle characteristicsignal comprises generating an in-path object signal.
 31. A method asrecited in claim 21 wherein generating a dynamic vehicle characteristicsignal comprises generating a wheel lifted signal.
 32. A method asrecited in claim 21 wherein generating a dynamic vehicle characteristicsignal comprises generating a body-to-road angle signal.
 33. A method asrecited in claim 21 further comprising entering a wheel liftdetermination when the body-to-road angle is above a predeterminedthreshold.
 34. A method as recited in claim 21 further comprisinggenerating a plurality of wheel speeds from a wheel speed sensors,identifying a wheel slip condition or wheel lock condition, generating alongitudinal speed signal in response to the dynamic vehiclecharacteristic signal during the wheel slip or wheel lock condition. 35.A method as recited in claim 21 wherein generating a dynamic vehiclecharacteristic signal comprises generating a body side slip signal. 36.A control system for an automotive vehicle comprising: a camera-basedvision system generating image signal; a dynamic control system; and acontroller coupled to the camera system and the dynamic control system,said controller generating an aggressive driving signal or loss ofcontrol signal in response to the image signal, said controllerincreasing the controlling the dynamic control system entry threshold inresponse to the aggressive driving signal and reducing the dynamiccontrol system entry threshold in response to the loss of controlsignal.
 37. A control system as recited in claim 36 wherein saidcontroller determines a lateral velocity signal in response to the imagesignal, said controller generating an aggressive driving signal or lossof control signal in response to the lateral velocity signal.
 38. Acontrol system as recited in claim 36 wherein the dynamic control systemcomprises a yaw stability control system.
 39. A control system asrecited in claim 36 wherein the dynamic control system comprises a rollstability control system.
 40. A control system as recited in claim 36wherein the loss of control signal comprises a road departure signal.41. A control system as recited in claim 36 wherein the camera-basedvision system comprises a front mounted camera.
 42. A control system asrecited in claim 36 wherein the camera-based vision system comprises afront mounted camera and a side mounted camera.
 43. A control system asrecited in claim 36 wherein the camera-based vision system comprises arear mounted camera.
 44. A method of controlling a dynamic controlsystem of a vehicle comprising: generating image signal; generating anaggressive driving signal or loss of control signal in response to theimage signal; increasing an entry threshold of the dynamic controlsystem in response to the aggressive driving signal; reducing the entrythreshold of the dynamic control system in response to the loss ofcontrol signal; and controlling the vehicle with the dynamic controlsystem.
 45. A method as recited in claim 44 wherein generating an imagesignal comprises generating an image signal from a stereo pair ofcameras.
 46. A method as recited in claim 44 wherein generating an imagesignal comprises generating an image signal from a front mounted cameraand a side mounted camera.
 47. A method as recited in claim 44 whereingenerating an image signal comprises generating an image signal from arear mounted camera and a side mounted camera.
 48. A method as recitedin claim 44 wherein the loss of control signal comprises a roaddeparture signal.
 49. A method of controlling a dynamic control systemof a vehicle comprising: generating image signal; generating anaggressive driving signal in response to the image signal; increasingthe controlling an entry threshold of the dynamic control system inresponse to the aggressive driving signal; and controlling the vehiclewith the dynamic control system.
 50. A method as recited in claim 49wherein generating an image signal comprises generating an image signalfrom a stereo pair of cameras.
 51. A method as recited in claim 49wherein generating an image signal comprises generating an image signalfrom a front mounted camera and a side mounted camera.
 52. A method asrecited in claim 49 wherein generating an image signal comprisesgenerating an image signal from a rear mounted camera and a side mountedcamera.
 53. A method as recited in claim 49 wherein the loss of controlsignal comprises a road departure signal.
 54. A method of controlling adynamic control system of a vehicle comprising: generating image signal;generating a loss of control signal in response to the image signal;reducing the entry threshold of the dynamic control system entrythreshold in response to the loss of control signal; and controlling thevehicle with the dynamic control system.
 55. A method as recited inclaim 49 wherein generating an image signal comprises generating animage signal from a stereo pair of cameras.
 56. A method as recited inclaim 49 wherein generating an image signal comprises generating animage signal from a front mounted camera and a side mounted camera. 57.A method as recited in claim 49 wherein generating an image signalcomprises generating an image signal from a rear mounted camera and aside mounted camera.
 58. A method as recited in claim 49 wherein theloss of control signal comprises a road departure signal.
 59. A controlsystem for an automotive vehicle comprising: a plurality of wheel speedsensors generating wheel speed signals; a camera-based vision systemgenerating image signal; a radar, lidar, or sonar-based systemgenerating environmental sensing signals; a dynamic control system; anda controller coupled to the camera system and the rollover controlsystem, said controller determining a first vehicle speed from the wheelspeed sensor signals, said controller controlling the dynamic controlsystem in response to the first wheel speed, determining a wheel lock orwheel slip condition from the wheel speed sensors, generating a secondvehicle speed in response to the image signal, said controllercontrolling the dynamic control system in response to the second vehiclespeed during a wheel lock or wheel slip condition.
 60. A control systemas recited in claim 59 wherein the dynamic control system comprises ananti-lock brake system.
 61. A control system as recited in claim 59wherein the dynamic control system comprises a traction control system.62. A control system as recited in claim 59 wherein the dynamic controlsystem comprises a roll stability control system.
 63. A control systemas recited in claim 59 wherein the dynamic control system comprises ayaw stability control system.
 64. A method of operating a dynamiccontrol system of an automotive vehicle comprising: generating wheelspeed signals from a plurality of wheel speed sensors; generating animage, radar, lidar or sonar-based signal; determining a first vehiclespeed from the wheel speed sensor signals; controlling the dynamiccontrol system in response to the first wheel speed; determining a wheellock or wheel slip condition from the wheel speed sensors; generating asecond vehicle speed in response to the image, radar, lidar orsonar-based signal; and controlling the dynamic control system inresponse to the second vehicle speed during a wheel lock or wheel slipcondition.
 65. A method as recited in claim 64 wherein controlling thedynamic control system comprises controlling a yaw control system.
 66. Amethod as recited in claim 64 wherein controlling the dynamic controlsystem comprises controlling a rollover control system.
 67. A method asrecited in claim 64 wherein controlling the dynamic control systemcomprises controlling a traction control system.
 68. A method as recitedin claim 64 wherein controlling the dynamic control system comprisescontrolling an antilock brake system.
 69. A control system for anautomotive vehicle comprising: means to determine the longitudinalvelocity of the vehicle; a camera-based vision system generating imagesignal; a dynamic control system; and a controller coupled to the camerasystem and the dynamic control system, said controller determining alateral velocity from the image signal, said controller determining aside slip angle in response to the lateral velocity and the longitudinalvelocity, said controller controlling the dynamic control system inresponse to the side slip angle.
 70. A control system as recited inclaim 69 wherein the dynamic control system comprises an anti-lock brakesystem.
 71. A control system as recited in claim 69 wherein the dynamiccontrol system comprises a traction control system.
 72. A control systemas recited in claim 69 wherein the dynamic control system comprises aroll stability control system.
 73. A control system as recited in claim69 wherein the dynamic control system comprises a yaw stability controlsystem.
 74. A method of operating a dynamic control system of anautomotive vehicle comprising: determining a longitudinal vehiclevelocity; generating image, radar, or lidar-based signals; determining alateral velocity from the image, radar, or lidar-based signals;determining a side slip angle from the longitudinal vehicle velocity andthe lateral velocity; and controlling the dynamic control system inresponse to the side slip angle.
 75. A method as recited in claim 74wherein determining a longitudinal velocity comprises determining alongitudinal velocity from a wheel speed sensor.
 76. A method as recitedin claim 74 wherein determining a longitudinal velocity comprisesdetermining a longitudinal velocity from the image, radar, lidar, orsonar-based signals.
 77. A method as recited in claim 74 whereincontrolling the dynamic control system comprises controlling a yawcontrol system.
 78. A method as recited in claim 74 wherein controllingthe dynamic control system comprises controlling a rollover controlsystem.
 79. A method as recited in claim 74 wherein controlling thedynamic control system comprises controlling a traction control system.80. A method as recited in claim 74 wherein controlling the dynamiccontrol system comprises controlling an anti-lock brake system.
 81. Acontrol system for an automotive vehicle on a road surface comprising: acamera-based vision system generating image signals; a dynamic controlsystem; a controller coupled to the camera system and the rollovercontrol system, said controller generating a low mu identificationsignal of the road surface in response to the image signal, saidcontroller controlling a dynamic control system in response to the lowmu identification signal.
 82. A control system as recited in claim 81wherein said controller generates a quantification of the low muidentification signal.
 83. A control system as recited in claim 82wherein the quantification corresponds to snow and rain.
 84. A controlsystem as recited in claim 81 wherein the dynamic control systemcomprises an anti-lock brake system.
 85. A control system as recited inclaim 81 wherein the dynamic control system comprises a traction controlsystem.
 86. A control system as recited in claim 81 wherein the dynamiccontrol system comprises a roll stability control system.
 87. A controlsystem as recited in claim 81 wherein the dynamic control systemcomprises a yaw stability control system.
 88. A method of controlling anautomotive vehicle on a road surface comprising: generating imagesignals; generating a low mu identification signal of the road surfacein response to the image signal; and controlling a dynamic controlsystem in response to the low mu identification signal.
 89. A method asrecited in claim 88 further comprising quantifying the low muidentification signal to form a mu quantification, wherein controllingcomprises controlling a dynamic control system in response to thequantification.
 90. A method as recited in claim 88 wherein thequantification corresponds to snow and rain.
 91. A method as recited inclaim 88 wherein controlling the dynamic control system comprisescontrolling a yaw control system.
 92. A method as recited in claim 88wherein controlling the dynamic control system comprises controlling arollover control system.
 93. A method as recited in claim 88 whereincontrolling the dynamic control system comprises controlling a tractioncontrol system.
 94. A method as recited in claim 88 wherein controllingthe dynamic control system comprises controlling an anti-lock brakesystem.
 95. A control system for an automotive vehicle comprising: acamera-based vision system generating image signals; a dynamic controlsystem having a first control strategy and a second control strategy;and a controller coupled to the camera system and the rollover controlsystem, said controller changing a first control strategy to a secondcontrol strategy in response to the image signal and controlling adynamic control system in response to the second control strategy.
 96. Acontrol system as recited in claim 95 wherein the dynamic control systemcomprises an anti-lock brake system.
 97. A control system as recited inclaim 95 wherein the dynamic control system comprises a traction controlsystem.
 98. A control system as recited in claim 95 wherein the dynamiccontrol system comprises a roll stability control system.
 99. A controlsystem as recited in claim 95 wherein the dynamic control systemcomprises a yaw stability control system.
 100. A method of operating anautomotive vehicle comprising: generating an image signals from a visionsystem; determining the presence of an in-path hazard in response to theimage signal; changing a first control strategy to a second controlstrategy in response to the image signal; and controlling a dynamiccontrol system in response to the second control strategy.
 101. A methodas recited in claim 100 wherein controlling the dynamic control systemcomprises controlling a yaw control system.
 102. A method as recited inclaim 100 wherein controlling the dynamic control system comprisescontrolling a rollover control system.
 103. A method as recited in claim100 wherein controlling the dynamic control system comprises controllinga traction control system.
 104. A method as recited in claim 100 whereincontrolling the dynamic control system comprises controlling an antilockbrake system.
 105. A control system for an automotive vehiclecomprising: a camera-based vision system generating image signals; adynamic control system; and a controller coupled to the camera systemand the rollover control system, said controller generating a trippinghazard signal in response to the image signal and controlling a dynamiccontrol system in response to the tripping hazard signal.
 106. A controlsystem as recited in claim 105 wherein the vision system comprises astereo pair of cameras.
 107. A control system as recited in claim 105wherein the vision system comprises a front mounted camera and a sidemounted camera.
 108. A control system as recited in claim 105 whereinthe vision system comprises a side mounted camera.
 109. A control systemas recited in claim 105 wherein the dynamic control system comprises ananti-lock brake system.
 110. A control system as recited in claim 105wherein the dynamic control system comprises a traction control system.111. A control system as recited in claim 105 wherein the dynamiccontrol system comprises a roll stability control system.
 112. A controlsystem as recited in claim 105 wherein the dynamic control systemcomprises a yaw stability control system.
 113. A control system asrecited in claim 105 wherein the dynamic control system comprises asuspension control system, said controller controlling the suspension tolower a center of gravity of the vehicle.
 114. A control system asrecited in claim 105 further comprising a warning device, saidcontroller controlling the warning device in response to the trippinghazard signal.
 115. A control system as recited in claim 114 wherein thewarning device comprises an audible warning device.
 116. A controlsystem as recited in claim 114 wherein the warning device comprises avisual warning device.
 117. A method of preventing a tripped rollover inan automotive vehicle comprising: generating an image, radar, lidar, orsonar-based signal; identifying a tripping hazard and generating atripping hazard signal in response to the image, radar, lidar, orsonar-based signal; and generating a warning signal from a warningdevice in response to the tripping hazard signal.
 118. A method asrecited in claim 117 wherein generating an image signal comprisesgenerating an image signal from a stereo pair of cameras.
 119. A methodas recited in claim 117 wherein generating an image signal comprisesgenerating an image signal from a front mounted camera and a sidemounted camera.
 120. A control system as recited in claim 105 whereingenerating comprises generating the image, radar, lidar, or sonar-basedsignal from a forward mounted system.
 121. A control system as recitedin claim 105 wherein generating comprises generating the image, radar,lidar, or sonar-based signal from a side mounted system.
 122. A controlsystem as recited in claim 105 wherein generating comprises generatingthe image, radar, lidar, or sonar-based signal from a rear mountedsystem.
 123. A method as recited in claim 117 further comprisingcontrolling a dynamic control system in response to the tripping hazardsignal.
 124. A method of preventing a tripped rollover in an automotivevehicle having a center of gravity, said method comprising: generatingan image, radar, lidar, or sonar-based signal; identifying a trippinghazard and generating a tripping hazard signal in response to the image,radar, lidar, or sonar-based signal; and changing the center of gravityto the vehicle counter to a roll direction in response to the trippinghazard signal.
 125. A method as recited in claim 124 wherein changingthe center of gravity comprises lowering an active suspension.
 126. Amethod as recited in claim 125 wherein lowering an active suspensioncomprises lowering the active suspension on one side of the vehicle.127. A method as recited in claim 124 wherein changing the center ofgravity comprises raising an active suspension.
 128. A method as recitedin claim 124 wherein changing comprises raising an active suspension onone side of the vehicle.
 129. A method as recited in claim 124 whereinchanging the center of gravity comprises lowering an active suspensionon one side of the vehicle and raising the active suspension on theother side of the vehicle.
 130. A method as recited in claim 124 whereingenerating an image signal comprises generating an image signal from astereo pair of cameras.
 131. A method as recited in claim 124 whereingenerating an image signal comprises generating an image signal from afront mounted camera and a side mounted camera.
 132. A control system asrecited in claim 105 wherein generating comprises generating the image,radar, lidar, or sonar-based signal from a forward mounted system. 133.A control system as recited in claim 105 wherein generating comprisesgenerating the image, radar, lidar, or sonar-based signal from a sidemounted system.
 134. A control system as recited in claim 105 whereingenerating comprises generating the image, radar, lidar, or sonar-basedsignal from a rear mounted system.
 135. A control system in anautomotive vehicle comprising: a camera-based vision system generatingan image signals; a dynamic control system; an integrated measurementunit generating sensor signals, said sensor signals comprising a drifterror; and a controller coupled to the camera-based vision system andthe integrated measurement unit, said controller correcting a drifterror in the sensor signals in response to the image signals to formcorrected sensor signals, said controlling the dynamic control system inresponse to the corrected sensor signals.
 136. A control system asrecited in claim 135 wherein the camera system comprises a pair ofcameras.
 137. A control system as recited in claim 135 wherein thecamera system comprises a front mounted pair of cameras.
 138. A controlsystem as recited in claim 135 wherein the camera system comprises afront mounted camera and a side mounted camera.
 139. A control system asrecited in claim 135 wherein the camera system comprises a rear mountedcamera and a side mounted camera.
 140. A control system as recited inclaim 135 wherein the dynamic control system comprises an anti-lockbrake system.
 141. A control system as recited in claim 135 wherein thedynamic control system comprises a traction control system.
 142. Acontrol system as recited in claim 135 wherein the dynamic controlsystem comprises a roll stability control system.
 143. A control systemas recited in claim 135 wherein the dynamic control system comprises ayaw stability control system.
 144. A method of controlling an automotivevehicle comprising: generating an image signals from a vision system;generating sensor signals from an integrated measurement unit whereinsaid sensor signal comprises a drift error; correcting a drift error inthe sensor signals in response to the image signals to form correctedsensor signals; and controlling a dynamic control system in response tothe corrected sensor signals.
 145. A roll stability control system foran automotive vehicle comprising: an active anti-roll bar system; acamera-based vision system generating image signal; and a controllercoupled to the active anti-roll bar system and the camera-based visionsystem, said controller generating a roll attitude signal indicative ofan impending rollover of the vehicle in response to the image signal andcontrolling the active anti-roll bar to prevent the vehicle from rollingover in response to the roll attitude signal.
 146. A roll stabilitycontrol system as recited in claim 145 further comprising a brakeactuator coupled to the controller, said controller controlling theactive anti-roll bar system and the brake actuator to prevent thevehicle from rolling over.
 147. A roll stability control system asrecited in claim 145 wherein the active anti-roll bar system comprises afront active anti-roll bar.
 148. A roll stability control system asrecited in claim 145 wherein the active anti-roll bar system comprises arear active anti-roll bar.
 149. A roll stability control system asrecited in claim 145 wherein the active anti-roll bar system comprises afront active anti-roll bar and a rear anti-roll bar.
 150. A method ofcontrolling roll stability of an automotive vehicle having a front andrear brake system, and a front and rear active anti-roll bar systemcomprising the steps of: generating image signals from a vision system;determining a roll angle estimate in response to the image signals;controlling an active anti-roll bar system in response to the roll angleestimate; and controlling a brake system in response to the roll angleestimate to provide a predetermined tire force vector.
 151. A method asrecited in claim 150 wherein controlling an active anti-roll bar systemcomprises controlling a front and rear active anti-roll bar in responseto the roll angle estimate.
 152. A method as recited in claim 150wherein controlling a brake system comprises controlling a front andrear brake controller in response to the roll angle estimate to providea predetermined tire force vector.
 153. A control system for anautomotive vehicle comprising: a level-based system; a camera-basedvision system generating image signal; and a controller coupled to theactive anti-roll bar system and the camera-based vision system, saidcontroller generating a pitch attitude signal and controlling thelevel-based in response to the pitch attitude signal.
 154. A controlsystem as recited in claim 153 wherein the level based system comprisesa suspension leveling system.
 155. A control system as recited in claim153 wherein the level based system comprises a headlight adjustmentsystem.
 156. A control system as recited in claim 153 wherein thecontroller determines a roll angle in response to the image signals,said controller controlling the level-based system in response to theroll angle and the pitch angle estimate.
 157. A method of controlling anautomotive vehicle comprising: generating image signals from a visionsystem; determining a pitch angle estimate in response to the imagesignals; and controlling a level-based system in response to the pitchangle estimate.
 158. A method as recited in claim 157 wherein the levelbased system comprises a suspension leveling system.
 159. A controlsystem as recited in claim 157 wherein the level based system comprisesa headlight adjustment system.
 160. A method as recited in claim 157further comprising determining a roll angle in response to the imagesignals and wherein controlling comprises controlling a level-basedsystem in response to the pitch angle estimate and the roll angle.